Item No.: NXF3~NXF12Ball: Gcr15 Steel, heat treated, HRC56 min; Precision ground, polished hard chromium plated Body: Alloy steel heat treated, Zinc plated; Race: Nylon polymer PTFE additive Sliding contact surfaces: Steel/NylonPhone: +86-592-580 8851 / +86-592-580 7618Email: sales@ldk-bearing.com ; benjamin@ldk-bearings.com